The Canadian Wildlife Health Cooperative (CWHC) has released a report characterizing some of the major threats impacting bat species present in Canada.
The organization utilized data from the CWHC Wildlife Health Information Platform national database and British Columbia Animal Health Centre database from the past five years to provide more information on how threats contribute to the mortality of Canadian bats.
The report's executive summary is provided below. You can view the full report on the CWHC's main page, or directly via this link.
The Canadian Wildlife Health Cooperative National Bat Health Report – 2021
By Jordi Segers, Scott McBurney, Megan Jones, and Patrick Zimmer
August 2021
Executive summary
It has become increasingly important in Canada to understand and manage bat populations through a holistic bat health approach. Bats are widely distributed throughout most of Canada, and dead and diseased individuals function as proxies for population and ecosystem health. The goal of this report is to synthesize the scanning and targeted surveillance data maintained in the Canadian Wildlife Health Cooperative (CWHC) Wildlife Health Information Platform (WHIP) database and the British Columbia Animal Health Centre database for bat species received by the CWHC nationally over the past five years to provide situational awareness about the causes of mortality affecting Canadian bats. This report does not take into account data from outside organisations. As such, we acknowledge that there may be other issues impacting the health of bats that are not identified through the CWHC’s scanning surveillance program.
The four main issues for bats identified through the CWHC’s wildlife health surveillance program are human-induced trauma, predation by companion animals, rabies, and white-nose syndrome, indicating that anthropogenic sources of trauma and infectious diseases are the main threats for the health of Canadian bat populations detected through this analysis. Rabies is a significant zoonotic disease and there is overlap in some instances where bats with human- or pet-induced trauma as a cause of death also test positive for rabies.
Interestingly, while wind farm development is well-documented in the peer reviewed literature as a significant cause of traumatic injuries and death in several bat species, the 5 year review of the CWHC’s bat surveillance data revealed little in terms of this threat to the health of Canadian bat populations. We believe that this significant data gap requires further investigation to better understand the severity of this potential threat in the Canadian context, particularly with the current increase in wind energy development across the country. Therefore, we strongly recommend promoting partnerships with various stakeholder groups to access and analyse the available bat mortality data from wind farms to assess the magnitude and species diversity of bat mortality at Canadian wind energy sites and determine the potential impact of this industry on bat health at a national scale.
Additional known threats to bat health that were not identified in this review include pesticides and other causes of toxicity, overheating events in bat houses, and trauma and stress associated with colony exclusion events from anthropogenic structures.